The field of the invention is vapor degreasers and the invention relates more particularly to vapor degreasers having a tank with a liquid solvent in the bottom which is heated to provide a solvent vapor zone used to remove soluble material from an object being degreased.
Conventional vapor degreasers are shown in U.S. Pat. No. 4,246,116 which was invented by the inventor of the present invention.
U.S. Pat. No. 5,048,548 shows a vapor degreaser with a three stage condenser/heat exchanger configuration for assisting in removal of solvent vapors so that they do not escape from the degreaser.
A door closure system for a vapor degreaser is shown in U.S. Pat. No. 5,261,736.
The solvents commonly used for vapor degreasing include methylene chloride, perchloroethylene, 1,1,1-trichloroethane, trichloroethylene, and trichlorotrifluoroethane. The vapors of some of these solvents are best eliminated as much as possible from the outside of the confines of a vapor degreaser. Although the solvents are heavier than air in the vapor state and tend to stay within the tank walls, breezes or drafts can cause the vapor to escape above the top of the tank walls. Past systems for preventing this have either been expensive or not sufficiently effective.